This invention relates to facsimile (FAX) communication.
Typically, in FAX communication, a FAX machine is connected directly via a telephone company line to the telephone company central office for access to the public switched telephone network. When remote telephone subscriber wants to send a facsimile to a local FAX machine, he gets access to the local FAX machine by dialing its telephone number. When the FAX machine answers, the remote telephone subscriber sends his FAX message.
When the sending party wants to identify the person who is to receive the FAX message, he typically writes that information on a cover sheet; someone at the local FAX machine then delivers the FAX message to the intended recipient based on the information on the cover sheet. In some FAX systems, the intended recipients can be indicated electronically by information which is exchanged after the call has been established. Typically, the information is communicated in accordance with a proprietary protocol restricted to machines of a given manufacturer.
One such scheme uses binary information that is passed (using Non-standard Facilities) as part of the FAX machine handshake. For example, the CCITT standard T.30 permits the use of Non-standard Facilities for providing such information. Such Non-standard Facilities have been used, for example, to set up mailbox facilities for FAX messages with the calling machine identifying the mailbox at the called machine to which the FAX message is to be delivered.
In a second arrangement, a FAX machine would use DTMF tones, sent by the originating FAX machine after the call has been established, to identify the intended recipient.
A third proposed technique would rely on special visible markings, on the first or each page of the FAX message, that would be recognized by the receiving FAX machine.